Assembly fixture



June 18, 1957 J. B. GRAY m 2,796,512

ASSEMBLY FIXTURE Filed Nov. 29, 1955 2 Sheets-Sheet 1 INVEINTDR JB.GRAY1I June 18, 1957 Filed Nov. 29, 1955 J- B. GRAY lll ASSEMBLY FIXTURE2 Sheets-Sheet 2 FIG 7 r/a' a ,v /5 /5 a/ a/ 7a 82 I 78 mvewrm J. B.GRAY .ZZI

ATTOQNEY United States Patent Ofiice 2,796,512 ASSEMBLY FIXTURE John B.Gray Ill, West Lawn, Pa., assignor to Western Electric Company,Incorporated, New York, N. 1., a corporation of New York ApplicationNovember 29, 1955, Serial No. 549,694

11 Claims. (Cl. 219-85) This invention relates to assembly fixtures andparticularly to fixtures for assembling elongated electrodes to supportwires of header members as are used in point contact type transistors.

In the manufacture of transistors of the type disclosed in theco-pending application of I. B. Gray III and W. R. Yeich, Serial No.549,695, filed on even date herewith, the resilient point contact wireelectrodes must be accurately located with respect to each other and theheader proper, and then be attached as by soldering to the headersupport wires therefor.

The object of this invention is a fixture which facilitates the accuratepositioning of the electrodes on the header supports for attachmentthereto.

According to the general features of the invention, ways on a basemember are adapted for receiving and positioning first a removableholder for preformed electrodes which are received by jaws movablymounted on the base and then a holder for header members which isclamped in the ways to position a header therein in a nest on the base.With both the electrodes and the header members positioned in the jawsand nest, respectively, the jaws are adjusted to accurately locate theelectrodes along the header support wires therefor and are then solderedin the adjusted positions.

These and other features of the invention will be more fully understoodfrom the following detailed description taken in conjunction with theaccompanying drawing in which:

Fig. 1 is an elevational view of a Western Electric Company type 1894transistor header-electrode piece part which is assembled in the fixtureshown in Figs. 2 through Fig. 2 is a top or plane view of a fixtureembodying the'general features of the invention showing schematically aresistance heating circuit for use therewith;

Fig. 3 is an enlarged view of the fixture of Fig. 2 as seen along theplane of line 3--3 thereof;

Fig. 4 is a view along the plane of line 4-4 of Fig. 3;

Fig. 5 is a view along the plane of line 55 of Fig. 3;

Fig. 6 is a partial plan view of the fixture showing an electrode holderpositioning therein for loading the electrodes into the jaws of thefixture;

Fig. 7 is a view of the electrodes and header as seen through amicroscope on the frame of the fixture and showing the special reticletherefor, and

Fig. 8 is an end view of the electrode holder.

Referring now to the drawing, the fixture of Figs. 2 through 8 isdesigned to receive a header member 17 (Fig. 1) and accurately positionelectrodes 22 and 23 on the header support wires 24 and 25,respectively, for attachment thereto. The basic components of thefixture inclue a main frame 11, a rotatable base 12 on the frame, a nestmember 13 for receiving header members 17, movable parallel ways 14 onthe base for receiving first a removable electrode holder 15 (shownpositioned in the ways in Fig. 6), and then a removable header memberholder 16 (shown positioned in the ways in Figs. 2 and the drawing, themicroscope has not been shown, as it is of conventional design:therefore, only the objective lens 21 (Fig. 3) is shown. In addition, aresistance heating circuit 26 may be utilized for heating the electrodesand support wires for soldering them in adjusted position.

Specifically, the 'nest member 13 is provided with a recess in the topside thereof for supporting the shoulder 31 of a header positionedtherein. The nest member 13 is attached to the end of block 36, the topside of which is provided with the ways 14. Block 36 in turn is mountedin dovetail engagement with a fixed member 32 attached to member 33 ofthe base. The ways block 36 and nest are movable along the member 32, anadjusting screw 34 which engages the end of the ways block 36 beingprovided for making this adjustment. A spring .35 compressed between themember 32 and the ways block 36 holds the ways block normally tensionedagainst the end of the adjusting screw 34. A toggle clamp 37 is providedin the other end of the ways block 36 and is used for holding the headerholder 16 in the ways 14 by means of a cantilever spring member 38. Inaddition to, carrying the spring 38, the toggle clamp also carries amember 39 for clamping the header wires 24 and 25- against terminal bars40 and 41, respectively, which are insulatedly mounted by insulator 43to the ways block 36. The end of the member 39 is provided with a rubbercompression member 42 for holding these support wires in contact withthe terminals. Terminals 40 and 41 are connected to the resistanceheating circuit 26 through leads 44 and 45, respectively. The operationof this cireuit will be discussed below.

Manually operable arms 58 and 59 for the electrode jaws 18 and 19 arepivotally mounted on blocks 48 and 49, respectively, which in turn aremovably mounted in dovetail engagement with Ways 50and 51, respectively,on the member 33 of the base. The block 48 of jaw 18 may be adjustedalong the ways 50 therefor by means of a thumb screw 52 shown in dashedlines in Fig. 2. The block 49 may also be moved along its ways 51 bymeans of a thumb screw adjustment 53, and in addition, may also be movedin the plane normal to the plane of motion along ways 51 by amicromanipulator mechanism, the adjusting screws 55 and 56 beingprovided therefor.

Arms 58 and 59 may be turned to an electrode receiv ing position asshown in Fig. 6, in which case, shoulders 60 on the arms 58 and 59 arealigned with the straight shank portion 61 of the electrodes 22 and 23.The jaws 18 and 19 are themselves pivotally mounted at 61 and 62,respectively, so that they may be opened to the positron shown in Fig. 6where they bear against stop pins 63 and 64, respectively. Pins 65 and66 which extend from the jaws may be manipulated manually for openingthe jaws. Springs 67 and 68 tensioned between pin 65 and a. post 71 onarm 58 and between pin 66 and post 72 on arm 59, respectively, hold therespective jaws in either the opened or closed position.

The electrode holder 15 comprises a main plate 78 and a ways positioningmember 80 attached thereto having shoulders 75 and 76 for fitting intothe ways 14 of the ways block 36 shown in dashed lines in Fig. 8.Shoulders 77 extend beyond the lower surface of and along each side ofthe main plate 78 of the holder and a pair of jaws 79, which arepivotally mounted to the main plate 78, are provided for holdingelectrodes 22 and 23 against the shoulders. Actuating pins 81 for thejaws 79 extend through a notched-out end portion of the holder so thatthe jaws may be manually manipulated from the top side of the holder asseen in Fig. 8. A spring 82 is tensioned Patented June 18, 1951 3between pins 81 of the jaws to hold the jaws normally in a closedelectrode engaging position. The electrodes are pre-formed before theelectrode holder is positioned in the ways: 14. a

The} header member holder 1-6: is a nylon- (or other insulator material)block having a plurality of holes extending therethrough for the wiresof the header and has parallel sides and shoulders for fitting into theways 14. a

The base 12 may be rotated on the frame 11- by means of a lever 85 whichis connected to the. end of a shaft 86 extending from the base 12. Thebase may be locked in a plurality of adjusted positions by means of a,pin 87 carried at the end of the lever 85' which may be posi tioned inholes 38 in the frame. 7

The resistance heating circuit 26 includes an' A. C.

source of power 90, a step down transformer 91 having:

low voltage, high current windings 92 and 93 which are connected throughswitches 94 and 95 to the fixture terminals and 41, respectively. Theother sides of the winding 92 and 93 are connected to the arms 58 and 59of the electrode jaws 18 and 19-, respectively. When the. electrodes 22and 23 have. been finally adjusted, the switches 94 and 95 may be closedto complete a circuit through the secondary windings of the transformer,the support wires 24 and electrode 22 on the one hand, and throughsupport wire 25 and electrode 23 on the other hand. Current through therelatively high impedance. of the mechanically connected support wiresand their respective electrodes produces sufiicient heat for meltingsolder which may be applied manually for soldering the electrodes to thesupport wires.

In operation, the two arms 58 and 59 are aligned as shown in Fig. 6, theblocks 48 and 49 being lowered so that the jaws are positioned beneaththe electrodes 22.and 23 of the holder 15, respectively, which is placedin the ways. The jaws are then opened and raised manually by means ofthe adjusting screws 52 and 53, respectively, until the electrodes arepositioned between shoulders 60 and the jaws 18 and 19 which, are thenmoved into clamping engagement. The electrode holder jaws 79 are thenopened and the holder is lifted' out, leaving the electrodes clamped injaws 18 and 19-, respectively. The

header member holder is then placed in the ways 14. so,

that the shoulder'31 of a header member in the-holder is positioned inthe recess in the nest member 13. and the toggle clamp is then closed toclamp the holder in the ways. The arms 58' and: 59' are then pivotallyturned to the position shown in Fig. 2. and the adjustable blocks 48 and49 and the-nest 13 adjusted to position the electrodes principles of theinvention. Numerous other arrangements may be readily devised by thoseskilled in the art which will embody the principles of the invention andfall within the spirit and scope thereof.

What is claimed is:

1. In a fixture for assembling elongated electrodes to support wires ofa header member, a base member, a nest member on the base for receivingthe header members, a removable holder for the electrodes havingreleasable clamping means for holding the electrodes in spaced relation,a removable holder for the header members, ways on the base forsuccessively receiving the holders, movable jaws on the base forreceiving electrodes from an electrode holder positioned in the ways,means for clamping the header holder in the ways to locate a headertherein in the nest member, means for adjustably positioning each of thejaws to locate electrodes therein on the respective support wires of aclamped header and for controlling the spacing between the ends of theelectrodes, and optical viewing means mounted on the base at a fixedposition from the header holder clamping means, said viewing meanshaving a reticle with a graduated scale for accurately gaging thespacing between the ends of the electrodes.

,2. A fixture for assembling elongated electrodesto. support wires of aheader member comprising a base member, a nest member on the base forreceiving the header members, a removable holder for the electrodeshaving releasable clamping means for holding the electrodes in spacedrelation, a removable holder for the header members, ways on the basefor successively receiving the holders, movable jaws on the base forreceiving electrodes from an electrode holder positioned in the ways,means for clamping the header holder in the ways to locate a headertherein in the nest member, means for adjustably positioning each of thejaws to locate electrodes therein on the respective support wires of aclamped header and for controlling the spacing along the support wires24-and 25 of the header as shown A in Fig. 7. Fig. 7 shows a specialgaging reticle which is provided for the eyepiece of the microscopewhich: is in fixed position on the frame and aligned so that the pointsof the electrodes are, in the approximate center of the field of vision.Guide lines 91 areprovided for the top of the header and line 90 forspacing the pointed ends of the electrodes from the header. Calibratedlines 92 are provided for gaging the spacing between the ends of theelectrodes 22 and 23. In the actual adjusting sequence, first the headeris adjusted by the thumb screw 34- until the header comes to the guideline 91. The electrode 22 is next brought down into contact with theheader lead or support wire 24 and then the right electrode 23 isadjusted in three dimensions so that it is against the header supportwire 25, and at a prescribed spacing from the other electrode, thespacing being gaged by means of the calibrated scale 92. The electrodesare then soldered one at a time as discussed above in connection withthe heat- ;ments are simply illustrative of theapplication of the a basemember,

betweenthe ends of the electrodes, and means for soldering theelectrodes to the header support wires 3. A fixture for locatingelongated electrodes on support wires of a header for attachment theretocomprising a nest member on the base for receiving the header members, aremovable holder for the. electrodes having releasable clamping meansfor holding the electrodes in spaced relation, a removable holder forthe header members, ways on the base for successively receiving theholders, movable jaws on the base for receiving electrodes from anelectrode holder positioned in the ways, means for clamping the headerholder in the ways to locate aheader therein in the nest member, andmeans for positioning the jaws to locate electrodes therein on therespective support wires of the clamped: header and for controlling thespacing between the ends of the electrodes.

4. Afixture for assembling elongated electrodes to support wires of aheader member comprising, a base member, a nest memberon the base. forreceiving the header members, a removable holder for the electrodeshaving releasable clamping means for holding the electrodes in spacedrelation, a removable holder for the header members, ways on the basefor. successively reciving the holders, movable jaws on the base forreciving electrodes from an electrode holder positioned in the ways,means for clamping the header holder in the ways, means for moving theways and nest member, means for soldering the electrodes to the headersupport Wires, optical viewing means mounted on the base at a fixeddistance from the ways,.a reticle for the viewing means having agraduated scale for accurately gaging the spacing between the ends ofthe electrodes and means for soldering the electrodes to the headersupport'wires.

5. A fixturev a'ccording to claim 3 having means for in a resistanceheating circuit for passing current serially through each of the supportwires and corresponding electrode when the electrodes have been movedinto contact with the support wires.

6. A fixture for locating elongated electrodes on support wires of aheader for attachment thereto comprising a main frame, a base memberrotatably mounted on the frame, means for rotating the base and lockingit in a plurality of rotated positions, a nest member on the base forreceiving the header members, a removable holder for the electrodeshaving releasable clamping means for holding the electrodes in spacedrelation, a removable holder for the header members, ways on the basefor successively receiving the holders, movable jaws on the base forreceiving electrodes from an electrode holder positioned in the Ways,means for clamping the header holder in the ways to locate a headertherein in the nest member, means for positioning the jaws to locateelectrodes therein on the respective support wires of the clamped headerand for controlling the spacing between the ends of the electrodes,optical viewing means on the frame positioned at a fixed distance fromthe ways, and a reticle for the optical viewing means having a graduatedscale for accurately gaging the spacing between the ends of theelectrodes.

7. A fixture for locating elongated electrodes on support wires of aheader for attachment thereto comprising a base member, a nest member onthe base for receiving the header members, a removable holder for theelectrodes having releasable clamping means for holding the electrodesin spaced relation, a removable holder for the header members, ways onthe base for successively receiving the holders, a pair of movableelements on the base, actuating means for the elements, an electrodereceiving jaw on each of the elements, spring biasing means for the jawsfor holding them in either an open or a closed condition, means forclamping the header holder in the ways to locate a header therin in thenest member, and means for positioning the jaws to locate electrodestherein on the respective support wires of the clamped header and forcontrolling the spacing between the ends of the electrodes.

8. A fixture for locating elongated electrodes on support wires of aheader for attachment thereto comprising a base member, a nest member onthe base for receiving the header members, a removable holder for theelectrodes having releasable clamping means for holding the electrodesin spaced relation, a removable holder for the header members, ways onthe base for successively receiving the holders, a pair of movableelements on the base, actuating means for the elements, pivotal memberson each of the elements, an electrode receiving jaw on each of thepivotal members, spring biasing means for the jaws for holding them ineither an open or a closed condition, means for clamping the headerholder in the ways to locate a header therein in the nest member, andmeans for positioning the jaws to locate electrodes therein on therespective support wires of the clamped header and for controlling thespacing between the ends of the electrodes.

9. A fixture according to claim 5 having spaced-apart contactor elementsbetween the ways for connecting the header support wires in theresistance heating circuit and a toggle action clamp on the base forclamping the header holder in the ways, said clamp also having aresilient element thereon for clamping each of the header support wiresinto electrical contact with the contactor elements.

10. A fixture for locating elongated electrodes on support wires of aheader for attachment thereto comprising a main frame, a base memberrotatably mounted on the frame, means for rotating the base and lockingit in a plurality of rotated positions, a nest member on the base forreciving the header members, a removable holder for the electrodeshaving releasable clamping means for holding the electrodes in spacedrelation, a removable holder for the header members, ways on the basefor successively receiving the holders, a pair of movable elements onthe base, actuating means for the elements, pivotal members on each ofthe elements, an electrode receiving jaw on each of the pivotal members,spring biasing means for the jaws for holding them in either an open ora closed condition, means for clamping the header holder in the ways,means for moving the ways and nest member, means for positioning thejaws to locate electrodes therein on the respective support wires of theclamped header and for controlling the spacing between the ends of theelectrodes, and means for connecting the jaws and the clamped headersupport wires in a resistance heating circuit for passing currentserially through each of the support wires and corresponding electrodewhen the electrodes have been moved into contact with the support wires.

11. A removable electrode holder for the fixture of claim 3 comprising amain plate having a pair of parallel sides, a shoulder extending beyondone side of the main plate along each of the two parallel sides, a pairof jaws pivotally mounted on said one side of the main plate for holdingelectrodes against the shoulders, actuating pins on the jaws extendingbeyond the other side of the main plate and a spring tensioned betweenthe pins for holding the jaws closed.

References Cited in the file of this patent UNITED STATES PATENTS2,602,872 Ziegler July 8, 1952 FOREIGN PATENTS 89,926 Sweden Aug. 10,1937

